JPS6311085A - Method and apparatus for driving monophase brushless motor - Google Patents

Abstract

PURPOSE:To enable rotor rotating position to be exactly detected, by stopping the conduction to a stator coil near the zero cross point of induced voltage, and by introducing only induced voltage and detecting the zero point. CONSTITUTION:A stator coil 3 is connected to the output terminal of an inverter circuit 6. A rotor position detection circuit 7 performs rotor position detection by introducing only the induced voltage to detect the zero point when the conduction is stopped to a stator coil 3 near zero cross point of the induced voltage. The rotor position detecting signal is sent out to a conduction control circuit 8 which sends out the conduction command to the stator coil 3 through an inverter 6. This conduction control circuit 8 is composed of an edge detecting section 8a, a driving section 8b, an measurement section 8c, a storing section 8d, a comparison section 8e, operation sections 8f and 8g, and timer sections 8h and 8i.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to driving a one-phase grassless motor, and in particular, to a method of detecting the circuit position of a rotor and driving it without using a position sensing element such as a Hall element. Regarding equipment.

<Prior art and its problems> Conventionally, as illustrated in FIGS. 3 and 4, this type of motor has magnetic poles 11a, 11f protruding from an annular stator core 11, and stator coils 11o, 11d.
are wound respectively to form a stator 10, and this stator 1
The rotor 12, which is permanently magnetized to N and S poles, is arranged concentrically with the magnetic poles 11a and 111) of
2 is rotatably supported by a bracket (not shown), and a position detection element 13 made of a Hall element or the like is disposed near the magnetic pole of the stator 10 so as to face the magnetic pole of the rotor 12. and form a DC power supply 14
Connect the positive side terminal of PVCP N P-type transistor (, Qρ emitter), and connect the collector of transistor Q, whose emitter is connected to the negative side terminal N of DC power supply 14, to the collector of this transistor (, Qψ), respectively. An inverter circuit 15 is formed, and the connection point between the collectors of this inverter circuit 15 is used as an output terminal, and both ends of the stator coils 11o and 11d are connected in series, S2, respectively, and a resistor R□ is connected to the DC power supply 14. The output terminal H of the position sensing element 13 is connected to the connection terminals P□ and N1 via
Connect a 1ft transistor to the base of Qx and the output terminal H2.

Connected to the Qρ pace, the output signal of the position detection element 13 turns on the transistors Qu-Qy and ~, Q-in alternately, causing a full 114Kt current to flow through the stator coil 11o, thereby causing the magnetized magnetic poles of the stator 10 to 11a,l
An attraction/repulsion force is applied between the lb barb 12 and the magnetic pole to generate rotational torque and rotate the rotor 12t.

However, in a motor configured in this way, the position detection element for detecting the rotational position of the rotor is connected to the motor body K.
Since the stator coil is connected to the control unit with an inverter circuit, the connection terminals and output terminals must be pulled out together with both ends of the stator coil and connected to the control unit equipped with an inverter circuit, which requires a large number of lead wires (6 on the upper side). In addition to requiring time and effort to wire the lead wires, the output signal level of the position sensing element is low and the impedance is high, so the longer the lead wires are extended to the outside, the more susceptible it becomes to noise, which can cause malfunctions. Therefore, it cannot be applied to equipment where the motor body and control unit are separated, and the position sensing element is thermally weak and requires heat dissipation means, and high precision is required for its installation. The mounting method has also become more complicated.
This has the problem of high cost.

In order to improve this, a three-phase brushless motor is already known in which the rotational position of the rotor is detected and driven by an induced voltage generated in a stator coil instead of a position detection element. In the case of a three-phase system, the commutation of the phase to be commutated can be detected by the induced voltage of the other two phases;
In the case of a phase, there is a problem in that all commutation timings must be detected from the induced voltage generated superimposed on the applied voltage of the own phase.

<Objective of the Invention> The present invention has been made in view of the above-mentioned points, and it is possible to drive a one-phase brushless motor by detecting the rotational position of the rotor from the induced voltage without using a position detection element. The object of the present invention is to provide a method and apparatus that can perform the following steps.

<Summary of the Invention> In order to achieve the above object, the present invention focuses on the fact that the rotational torque generated in the rotor is extremely small near the zero cross of the induced voltage generated in the stator coil, and the transistors of the inverter circuit are connected near the zero cross. This is characterized in that the zero point of the induced voltage is detected with all the stator coils turned off, and the current flowing through the stator coil I is reversed based on this detection signal.

<Embodiments of the Invention> In order to facilitate understanding of the present invention, the relationship between the induced voltage of the stator coil and the magnetic pole position of the rotor will be explained. Now considering the motor in a simulated manner as shown in Fig. 5, when the magnetic flux per magnetic pole of the rotor is B, the stator coil L
The vector component φ of the rotor's magnetic flux interlinking with the It is rotating at an angular velocity ω, and if the angle θ between the stator coil /l/L and the magnetic flux B of the rotor is at time t, then the amount of change in φ at time t, that is, the time differential of φ dφ/dt, is = - 13ω sin ωt (2), so the induced voltage E of the stator coil L is (however, 0
20℃) Therefore, when ωt=θ=90°, the maximum positive value ωt=θ=2
When the angle is 70°, the voltage becomes a sinusoidal wave with a negative maximum value.

On the other hand, when a current 1 is passed through the stator coil/I/L, assuming that the magnetic field H created by the current 1 is a parallel magnetic field in relation to the force F acting on the rotor, as shown in Figure 6, the force acting on the rotor's magnetic poles is The force F is expressed as F: B lH (4) (where l is the length of the magnetic pole), and this force F is the component that acts in the direction of pushing or pulling the rotor toward the magnetic pole. and a component that acts in the direction of rotating the magnetic poles, and only the latter contributes as a force that rotates the rotor.

Therefore, the force that rotates the rotor FtJ/iF1. = F
5j-no= B I Hsinθ ・1 old・(5
), this is the rotational torque of the motor.

The above Ft has a positive maximum value when 0 = 90° in the region where θ is 0° and θ<180°, so in order to efficiently rotate the motor in the same direction, θ = 90°
It is sufficient to apply current around θ, and almost no rotational torque can be obtained in the range where θ is close to 0° and 1800°.

When the rotor rotates further and θ reaches a region of 180° or more, if the current i is allowed to flow in the same direction as shown in Fig. 6, the rotational torque Ft will be negative, as is clear from equation (5) above. If the current 1 is passed in the opposite direction in this region, the rotational torque Ft will be 't=-BIHsi, no...
・・・・・・(6) (However, 180°〈θ〈360°
) As a result, the above FJE becomes positive, so the rotor continues to rotate. In this region, the maximum positive value is reached when F = 270°, so in order to efficiently rotate the rotor, the current 1 must be applied in the opposite direction to that shown in Fig. 6, centering on θ; 270°. It would be a good idea to let it flow.

The above results are illustrated in FIG. 7 (the voltage applied to the stator coil p is omitted). According to the figure, the rotational position of the rotor and the induced voltage correspond perfectly, so the rotational position of the rotor can be detected by the induced voltage, and the polarity switching timing (commutation timing) of the current 1 is It can be seen that this coincides with the zero point of the induced voltage.

Therefore, the present invention focuses on the point that the rotational position of the rotor can be detected by deriving only the induced voltage by some means from the rotating motor that is energized at the above-mentioned timing and detecting the zero point. At the point when the voltage should be commutated, that is, near the zero point of the induced voltage, the rotational torque Ft is almost zero.)
, the current 1 only contributes to the pulling force on the rotor;
This was done by focusing on the point that even if the current 1 is once cut off in this vicinity, the generated rotational torque Ft will not change significantly.

Embodiment f of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 2 is a basic configuration diagram of the motor. In the figure, reference numeral 1 denotes a stator, and the open end of the stator yoke 2 is made of electromagnetic steel sheets punched out in a U-shape, laminated and fixed by rivets (not shown), and has magnetic poles 2a and 21 facing each other with arc-shaped tips. ), and a stator coil 3 in which a coil conductor is wound around a coil frame 3a is attached to the yoke portion 2cll'c. 4 is N.

The rotor is permanently magnetized to the S pole, and is arranged concentrically with the magnetic poles 2a and 2- of the stator 1, and is carefully inserted into the rotating shaft 4; It is rotatably supported, so-called skeletal) V
It is configured as a 1-phase brushless motor.

Both ends of the stator coil/L/3 are connected to the DC power supply 5 through terminals P, N?, as shown in FIG. The output terminals of the inverter circuits 6 are respectively connected to the output terminals of the inverter circuits 6 connected thereto. As described above, this inverter circuit 6 connects the emitters of the positive side connection terminals P K P NP type transistors (, ~), connects the emitters of these transistors to the negative side connection terminal N of the DC power supply 5, Connect the collectors of the connected transistors Q and ~, respectively).

It has a ridge shape, and the connection point between the collectors is used as an output end to send out output.

A free wheel diode "111 Dv+Dxt Dy7" is inserted between the collector φ emitter of each of the transistors Qu-Qv, Qx, and Q in the opposite direction. Reference numeral 7 denotes a position detection circuit for detecting the rotational position of the rotor 4, which connects the collector of a transistor Q whose emitter is connected to the negative side connection terminal N of the DC power supply 5 to a constant voltage power supply V via a collector resistor R1. Connect the connection point of the above transistor (and ~) to the base of this transistor Q through a base resistor R2'e, insert a resistor R3 between the base and emitter of the transistor Q, and connect the base of the transistor Q When the induced voltage generated in the stator coil (V3) is a positive half wave with the collector of the stator coil as the output terminal, '
The output signal of the L level is sent out as a position detection signal, and when it is a negative half wave, the K output signal of the H level is sent out as a position detection signal.

Reference numeral 8 denotes an energization control circuit that sends an energization command to the nutator coil 3 via the inverter circuit 6 in response to the position detection signal. This will be explained. Reference numeral 8a denotes an edge detection section connected to the output terminal of the position detection circuit 7, which differentiates the position detection signal that is inverted at the zero point of the dielectric voltage, performs double-wave rectification, and sends out a pulse signal that makes it possible to detect a rising edge. It is.

8. A flip-flop circuit FF connected to the output terminal of the edge detection section 88 and inverting the output signals of the output terminals Q and Q at the rising edge υ of the input, and this flip-flop circuit F.
It is equipped with AND circuits AND2 and AND2 whose input terminals are respectively connected to the output terminals Q and Q of F, and this AND circuit A
One of the output terminals of the ND circuit is directly connected to the base of the transistor Qf, the other is connected to the base of the transistor (through the NOT circuit N1), and one of the output ends of the AND circuit AND2 is directly connected to the base of the transistor Qρ, and the other is connected to the NOT circuit. connected to the base of the transistor Qf through N2, respectively,
At the rising edge of the input signal, transistor Qu-Q; V, Qx,
This is a drive unit that controls on/off of Qy. 8. A period measuring section that is connected to the output terminal of the edge detecting section and measures the period from the rising edge of an input signal to the rising edge of the next input signal (that is, the half-wave period of the induced voltage). This period measuring section counts the clock signal at the rising edge of the signal, increments the count at the rising edge of the next input signal, outputs the data, and clears the data to prepare for the next count. That is, the period measurement section 8
゜ measures the rotation period of the rotor 4 every 1/2 period and transmits the data. 8d is connected to the output end of the measuring section 8°, takes in the counted up data, stores it once, and outputs it, and when the next data is sent from the measuring section 8-1, it also outputs the accumulated data. This is a data storage section that can be cleared and replaced with new data. A comparison section 88 is connected to the output ends of the measuring section 8.degree. and the storage section 8d, and sends out an output signal comparing the magnitude of the image input signal (that is, the current data and the previous data). 8f, 8〆 Connected from the output end of the measuring section 8゜, standby time 1 energizing time? The first step is to set each calculation. Second
In the calculation unit, a coefficient (for example, waiting time T0 is set to 180
If the angle is 30°, the next waiting time T is calculated by multiplying by 30/180), and this calculated value is used by the comparison section 8.
When receiving a comparison signal with the relationship 62 > - (current data) < (previous data), the above calculated value is corrected to be smaller (for example, multiplied by a coefficient of 99/100), and the relationship is reversed. When a certain comparison signal is received, the above calculated value is corrected to be larger (for example, multiplied by a coefficient of 101/100) and the next waiting time Tl is set. The next energizing time T is calculated by multiplying the data output from 8° by a coefficient (for example, if 1200 is 1200 for the energizing time T2k l 80°, then 120/180), and this calculated value is applied as described above. The next energization time T2 is set by correcting the comparison signals from the comparator 8 and the comparator 8, and these set values are output respectively. 8fi, si: is the above calculation unit 8f
, 8F! ? The first one is connected to each output terminal and clocks a standby time of 9 energization times. The second timer section responds to the rise of the output of the first timer section 8 and the edge detection section 88, and counts, for example, a clock signal. ) is the waiting time T output from
The second timer section 81 outputs a 'H' level output signal when it matches the set value of the first timer section 8M7). At the rising edge of , an output signal of 'H level is sent from the output terminal to the AND circuits AND circuits AND circuits AND2 of the drive section 8 to count, for example, a clock signal, and this count value is output from the second calculation section 8-). Energization time T
When it matches the set value of 2, a time-up occurs and the output signal is inverted to 'L' level/1/.

Next, its operation will be explained. First, in the initial state, data of 1/2 rotation period is not taken into the period measuring section 8 (>data storage section 8d. Therefore, the rotation frequency corresponding to the rotational frequency (for example, 10H2) at the time of startup of the rotor 4 is 1/2
@The time data of the J rotation period is stored in advance at the measuring section 8゜.
It is taken into the storage section 8d.

Transistor % of inverter circuit 6 * Qwe QxI
Q: All Ys are also in the off state. In this state, the DC power supply 5 is applied, and the constant voltage power supply circuit 9 generates a constant voltage power supply ■.

is supplied to each circuit as control power. As a result, the output of the position detection circuit 7 is inverted to the 'H level, and the edge detection section receiving this differentiates the input and sends out a rectified pulse signal. The flip-flop circuit FF that received this output terminal Q at the rising edge of the input.

The output of Q is inverted and sent to AND circuits AND, AND2, respectively, but the other input of AND circuits AND and AND2 is '''
Since it is at the L' level, the output is at the 'L' level and the transistor %-Qv'Q'x' remains off.

On the other hand, upon receiving the pulse signal from the edge detecting section 8a, the measuring section 84 counts up by manual startup and sends the data to the calculating sections 8f and 8. The waiting time is calculated by multiplying the input value of the calculation unit 8 by a coefficient (for example, 30/180), and this calculated value is sent to the timer unit 8f as the current waiting time T.

At this time, since the data in both the measurement part 8° and the storage part 8d are the same from the comparison part 8e, a comparison signal of magnitude is not sent out and the above-mentioned calculated value is not corrected. Then, the clocking operation is started at the rising edge 9 of the output of the timer section 8 and the edge detection section 8Fp, and when the count value matches the set value of the standby time T of the calculation section 8, the time is up and the output terminal On the other hand, the arithmetic unit 8 receives the data from the measuring unit 8c and adds a coefficient (for example, 12
0/180) to calculate the energization time, and this calculated value is sent to the timer section 81 as the current energization time T2 (the above-mentioned calculated value is not corrected for the reason mentioned above). In response to this, the timer section 81 starts the clocking operation when the output of the timer section 8f) is inverted to the 'H level. Invert the transistor%.

As a result, a current flows through the path of 5→Se3-Qxr, magnetizing the stator 1's magnets, and positioning the stator 1 at a predetermined position (for example, the second
The repulsive force of the attraction 9 acts between the magnetic poles of the rotor 4, which was stopped at the position shown in the figure), and rotational torque is generated in the rotor 4.
The rotor 4 begins to rotate in the direction of the force indicated by the arrow CW in the figure (i.e.
to start). At this time, the transistor Q of the position detection circuit 7
The pace current does not flow through the machine and it remains off, and the position detection signal is at ``HH''.

Then, when the count value matches the set value output from the calculation section 8, the timer section 8i inverts the output signal at the output end to 5L level upon time-up, and turns off the transistors (,...). At this time, Q is finally off\).As a result, the power supply to the data coil/I/3 is stopped, and due to the negative induced voltage generated by the rotation of the rotor 4, 3→"u-5→Dy-3 is turned off. A current flows through the path, and the transistor Q is at the 'H' level.Then, the rotor 4 rotates due to inertia due to the above-mentioned energization stop, and its magnetic pole center passes through the magnetic pole centers of the magnets m2a and 2b of the stator 1. At this point, the induced voltage changes from negative polarity to positive polarity, so this positive induced voltage causes a pace current to flow through the transistor Q through the path 3 → R2 → base emitter of Q → Dx → 3, Transistor Q turns on, and the position detection signal is inverted to 1L level (that is, the zero point of the induced voltage is detected).

In response to this, the edge detection section 8a of the energization control circuit 8 differentiates and rectifies the input and sends the pulse signal to the flip-flop circuit FF of the drive section 8b.
For F, the output terminals Q and Q are set to ``L'' at the rising edge of the input.
, are inverted to 'H', respectively. On the other hand, the edge detecting section 8 - the measuring section 8 which has received the pulse signal, transfers the initial setting data to the storage section 8d and stores it in response to the pulse signal received at the time of startup, and starts counting. The period from the pulse signal to receiving the current pulse signal (
The time corresponding to the period from the zero point of the induced voltage to the next zero point (in other words, 1/2 rotation period) is counted up using the current pulse signal, and the data is sent to the calculation unit 8.
f, s8 and the comparison unit 8e, and the comparison unit 8
≠An output signal obtained by comparing the magnitude of this data with the data outputted from the storage section 8d is sent to the calculation sections 8f and 8g. Receiving these data, calculation units 8f and 8-1 calculate the standby time T and energization time T2 as described above, and the comparison unit 8-
When a comparison signal with the relationship (current data) < (previous data) is received, the above-mentioned calculated value is corrected to become smaller, and the waiting time is increased.

Setting the energization time T2, the timer section 8h, 81. (In other words, when the above relationship exists, it is determined that acceleration is occurring, and an increase in rotational frequency is predicted and correction is made accordingly).

At this time, the measurement unit 8 - the data measured this time are stored in the storage unit 8.
d, and counting starts from the rising edge of the input of the pulse signal, and the time of 1/2 rotation period is measured.

Then, as described above, the timer section 8h starts clocking operation at the rising edge of the pulse signal of the edge detection section 88, and when the count value matches the set value outputted from the calculation section 8 seconds, the timer section 8h starts the time-up operation. In response to this, the timer section 81 inverts the output of the output terminal to 1H level at the rising edge of the input, and inverts the output of the AND circuit AND2 to 1H level. , transistor Q, ,Q, ,z
It is turned on and a current flows through the stator coil 3 along the path 5→→3→Qf45, and the magnetic poles 2a and 2 of the stator 1 are magnetized to have opposite polarities to those described above, thereby applying rotational torque to the rotor 4 and accelerating it. As described above, when this energization matches the set value of the energization time T2 calculated and set by the calculation unit 8gIC, the output signal of the timer unit 8f) is stopped by inverting to the L level, and the rotor 4 continues to rotate due to inertia force. Then, using the position detection signal that is inverted at the point when the induced voltage changes from positive polarity to negative polarity (zero point), the 1/2 rotation period is measured and the standby time T 9 energization time T2 is calculated and set. Based on the value, after stator coil/I/3'e standby time T,
The rotor 4 is further accelerated and drawn into synchronous operation by repeating the above-mentioned operation in which the energization is switched and the energization time T2 begins.

In addition, the operation during deceleration is a standby time of T and a power-on time of T.
The operation is the same as described above except that the correction made at the time of calculation setting No. 2 is made to be larger than the calculated value, so a description thereof will be omitted.

According to the above embodiment, since the current flow is stopped before the induced voltage reaches zero cross, it is possible to derive only the induced voltage generated in the own phase and accurately detect the zero point, and furthermore, the zero point of the induced voltage can be detected accurately. Since the standby time and energization time are calculated and set based on the data measured for the period from one point to the next zero point, that is, the 1/2 rotation period of the rotor, the rotational torque acts effectively on the rotor. It is possible to energize only for a certain period of time according to the rotation period, and the motor can be accelerated and
Since the standby time and energization time are corrected in accordance with deceleration, the motor can be driven efficiently.

In the above embodiment, it has been explained that the edge detection section 8 differentiates the input, performs double-wave rectification, and sends out a pulse signal, but this pulse signal and the output signal of the timer section 8 for the energization time are connected to the knot circuit. If the output is configured to be logically ANDed with the output signal of the delay circuit that rises with a longer delay time than the pulse width of the spike voltage that occurs when the current in the stator coil is cut off, the induced voltage can be zero. A position detection signal that is inverted at a point can be accurately output from the female edge detection section.

FIG. 8 shows another embodiment of the present invention, in which the stator coil 3 of the stator 1 is connected via a DC power supply 51C inverter circuit 6, and position detection is performed at one of the output ends of the inverter circuit 6. Since they are the same in that they are formed to be connected to the circuit 7, a description thereof will be omitted and similar members will be described with the same reference numerals.

8 is an energization control circuit that sends an energization command to the stator coil/I/3 via the inverter circuit 6 based on the position detection signal from the position detection circuit 7, as described above.

This connects the differential circuit DF to the output terminal of the position detection circuit 7.
A rectifying circuit RF is connected through the rectifying circuit RF to form an edge detecting section 8a that differentiates the input signal, performs double-wave rectification, and sends out a pulse signal from the rectifying circuit RF that enables the detection of a rising edge. , the input terminal CL of a latch circuit LAl consisting of a D-type flip-flop that inverts the output signal at the rising edge of the input and holds it until reset is connected to the output terminal of the rectifier circuit RF. Latch circuit L
A flip-flop circuit FF is connected to the output terminal Q of the A circuit through a delay circuit TDl that delays the input by a waiting time T and outputs the output, and inverts the output signal at the rising edge of the input.
Connect the input terminal OL of this flip-flop circuit F.
AND circuit AND2 at the output terminals Q and Q of F□.
Connect the input terminals of the above AND circuit, and connect the output terminals of the AND circuit to one directly to the transistor Q, fD base, the other to the NOT circuit Nl, and the other to the NOT circuit B2.
Transistor envy through.

are connected to the bases of the latch circuit LA□ to form a driving section 8b, and the output signal of the latch circuit LA□ causes the delay circuit TD1 to be connected to the transistors Qu, Qv, Q! x, Q$ on/off control. And the delay circuit TD
An oscillation circuit oSC that sends out a clock signal from the output end of the
The input terminal of a counter circuit CU (connected to jK and connected to NOT AND circuit A connected from the rectifier circuit RF via circuit N3
Connect to the input terminal of ND4゜AND5, and this AND circuit A
The output terminals of ND4゜AND5 are connected to the input terminals U and D of the energization time setting circuit CU2, which consists of a U/D counter that counts up or down at the rising edge of the input and outputs it as a binary code of multiple bits (for example, 8 bits). The energization time setting circuit CU2 has a rotation frequency (for example, 10 H2) at startup for a 1/2 rotation period based on K. The time T2 (for example, the time corresponding to 120') is counted in advance, and the output terminals are connected to the B input terminals of a comparison circuit COM□ consisting of a magnitude comparator, and the A input terminals of this comparison circuit COM are connected. By connecting the output terminals of the counter circuit CU, the comparator circuit COM outputs an "IH level" output signal from the output terminals A and B when the A and B signals match. This comparison circuit COM
The output terminal A=B of the circuit is connected to the input terminal OL of a latch circuit LA2 consisting of a D-type flip-flop which inverts the output signal at the rising edge of the input and holds it until it is reset, and the above-mentioned counter circuit. Via the reset input terminal R of CU□ and a delay circuit TD2 that outputs a signal with a delay time td2 longer than the pulse width of the spike voltage that occurs when the current in the stator coil 3 flowing at the maximum load of the motor is cut off. They are respectively connected to the reset input terminal R of the latch circuit LAY. The latch circuit LA2 has its reset input terminal R connected to the output terminal of the delay circuit TD via a Barne generation circuit MB which outputs a one-shot pulse at the rising edge of the input, By connecting the input terminal of the AND circuit AND2 of the driving section 8b to the output terminal Q, when the output signal of the output terminal A=B of the comparator circuit COM□ is inverted to 1H level, the output of the output terminal Q is ``I
Turn to L level and stop energizing the stator coil.
This is maintained until the next start of energization. Also, the output terminal Q of this latch circuit LA2 is connected to the oscillation circuit O8C.
At the rising edge of the input, it is counted up through the AND circuit AND6 connected from
This counter circuit CU3 has its reset input terminal R connected to the output terminal Q of the latch circuit LA2, and its output terminal has a comparison circuit consisting of a magnitude comparator. The A-side input terminals of C0M2 are connected respectively, and the B-side input terminal of this comparison circuit C0M2 is connected to the time from energization stop to energization start, specifically, the zero point of the induced voltage from energization stop to stator coil/I/3. The time T3 (hereinafter referred to as detection time), the waiting time T The energization stop time setting circuit CU4 consists of a counter whose count is preset and output using a binary code.
The output terminals of the comparator circuit COM2 are connected to the input terminals of the AND circuit AND4, and the output terminals A (B of the comparator circuit COM2 are connected to the input terminal of the AND circuit AND5, and the output terminals A) and B of the comparator circuit COM2 are connected to the input terminal of the AND circuit AND4. C0M2 compares the magnitude of both human input signals A and B, and when the relationship is A and B, the above energization time setting @ J path CU2 is downcounted by the edge detection unit 8.0 pulse signal, and the relationship between A) and B. , an output signal of "H level" is sent out in order to cause up-counting. That is, the energization time T2 with respect to the 1/2 rotation period of the rotor 4 is corrected.

A resistor R4 is inserted in series between the output terminals of the constant voltage power supply circuit 9 at the set input terminal S of the latch circuit LA.
The above-mentioned knot circuit N4 of ○PC is a starting circuit formed by connecting the input end of the knot circuit KN4 to the connection point between the capacitor and the capacitor C.
By connecting the output terminal of the latch circuit LA, the output signal of the output terminal Q of the latch circuit LA is inverted to 'H level by a one-shot pulse signal at the time of starting.

Next, its operation will be explained with reference to FIGS. 9 and 2. By applying the DC power supply 5 (at time t0 in FIG. 9), the constant voltage power supply circuit 9 supplies each circuit with a constant voltage power supply v- (as a control power supply. In this case, the output signal of the position detection circuit 7 is 1.
H Lebel and Nasi, starting circuit ○Latch circuit LA that receives one-shot P/L/N signal from PC and its output terminal Q
The output signal of + % is transmitted to the H# level, and
By holding this and inverting it, the delay circuit TD responds to the rising edge of the input, and after the waiting time Tl, the output signal becomes "IH".
Turn it over to the level (at the time of construction t in Figure 9). In response to this, the flip-flop circuit FF inverts the output signals of the output terminals Q and Q to 5H' and IL' respectively at the rising edge of the input (
Figure 9 TD engineering). As a result, the output signal of the AND circuit AND circuit is inverted to ``H level'', turning on the transistors (at time t in Figure 9), and the stator coil 3 is
A current flows through the path 3 → roar 5 and the magnetic pole 2a of the stator 1
, 2'%E magnetized and stopped at a predetermined position (for example, the position shown in FIG. 2) by a positioning means (not shown), an attraction 9 repulsive force is generated between the rotor 4 and the magnetic poles of the rotor 4.
Rotational torque is generated, and the motor starts to rotate (ie, starts) in the direction of the arrow CW force shown in Fig. 2, for example. At this time, a pace current flows between the transistor Q and the emitter of the transistor Q of the position detection circuit 7, turning the transistor Q on, and the position detection signal is reversed to the L level. 9 [at the time of Nt construction]. In response to this, the falling edge of the edge detector 8 on the inferior side is differentiated and rectified, and a pulse signal is sent to the latch circuit LA, but since the latch circuit LA is held, the output signal is H Lebel's t-.

Then, the 5H# level/V of the delay circuit TD□ (7)
The AND circuit AND3 that receives the output signal receives the clock signal from the oscillation circuit O8C at its other input terminal, so
The same signal as the clock signal is sent from the output terminal, and the counter circuit CU that receives this counts up at the rising edge of the input and converts it to the comparison circuit CO using a multi-bit binary code.
Output to the A side output end of M workpiece. Since the comparator circuit C0M1 receives at its EM input terminal the output signal of the preset energization time T2 in the form of a multi-bit binary code, the energization time setting circuit CU2 receives it when both the A and B side input signals match. , an output signal of "H level" is sent from the output terminal A=B (point tP in Figure 9).The AND circuits AND, , AND5 connected to the input terminals U and D of the energization time setting circuit CU2, respectively, receives a pulse signal from the edge detection section 8-1, but since the other input is at the 1L level, both output signals are at the 5L level.

The output signal of the output terminal A=B of the above comparison circuit COM is 'H
The counter circuit CU is reset by inversion to the level, and the latch circuit LA2 changes the output signals of the output terminals Q and Q to 'H', ', ', respectively at the rising edge of the input.
Inverts to L' level and holds this until reset,
By inverting the output terminal Q of this latch circuit LA2 to 'L' level, the output signal of the AND circuit AND circuit becomes 'L'.
(the output signal of AND2 remains at L level), and turns off the transistors Q, . That is, the stator coil /L/3 stops being energized after the energization time T2.

At this time, the current flowing through the stator coil 3 is cut off by turning off the transistors Qv and Qρ, and a spike voltage is generated with the opposite polarity to the applied voltage due to the release of the energy stored in the stator coil V3. Since the transistor Q of the detection circuit 7 is once reverse biased and turned off, the position detection signal is once inverted to the 'H' level and further rotated to 'LL' level (Fig. 9, 7). Pulse signals are sent from 8a to the latch circuit LA at the rising and falling edges of the input (Fig. 9, 8a), but the latch circuit LA connects the comparator circuit COM to its reset input terminal R. Output end A=B
' of the delay circuit TD2 which receives the output signal of 'H level from '
It does not receive the output signal of the H level, and the output signal of the output terminal Q remains unchanged without being inverted! It is held (at the 'H lever) (Fig. 91 TD work).

In other words, the transistor that was on in the inverter circuit 6 (
On the upper side, even if a spike voltage is generated due to the interruption of the current flowing to the stator coil /L/3 when the coil (~, 叛) is off, there will be no malfunction due to this.

Then, as the spike voltage disappears, the position detection signal is generated by the positive induced voltage, which causes a base current to flow through the transistor Q□ through the path 3→R2→base-emitter of the Q component→Df+3, and the transistor Q turns on. , %L level (point tP in Figure 9). This L level position detection signal is generated when the rotor 4 rotates due to inertia force due to the stop of energization to the stator coil/L/3, and its magnetic pole center is located at the stator 1.
magnetic pole 2a.

Since the induced voltage changes from positive polarity to negative polarity when passing through the center of the magnetic pole 2b, the transistor Q is reverse biased and turned off, and is reversed to 'H level, that is, the zero point of the induced voltage is detected. (Time t5 in Figure 9).

At this time, the time when the transistor is turned off (t2 in FIG. 9)
After the delay time td2 has elapsed since point ) (time t4 in Figure 9)
, the output signal of the delay circuit TD2 is inverted to 1H level, the output signal of the output end Q is inverted to ``IL level, and the delay circuit TD is reset and its output signal is inverted to ``L level'' (Fig. 9). TD) The edge detection unit 8 receives the position detection signal inverted to the above 'H level, and then differentiates the rising edge of the input and sends out a rectified pulse signal.Receiving this, the latch circuit LA□ detects the rising edge of the input. The output signal of the output terminal Q is inverted to 'H level and held (9th
Figure t5). After receiving this delay circuit TD, the output signal is inverted to 5H level after being delayed by the standby time T (point tij in FIG. 9). Flip-flop circuit F that received this
For F, when the input rises, the output signal t, % of the output terminal Q,
A pulse generation circuit M that inverts the L# and %HI levels and outputs at the rising edge of the input.
Laso 1,000 circuit LA by one shot pulse signal of B engineer
2 is reset and the output signals of its output terminals Q and Q become 1'
Inverted to L' and 'H' levels (Fig. 9 t)
6 time points). As a result, the output signal of the AND circuit AND2 is inverted to 1H level, and the output signal of the transistor %, Q. Turn on e (at time t6 in Fig. 9), and set stator coil/I/3 to 5→(
energize through the path →3→bus5 and let the current flow in the opposite direction to the above (energizing direction in Fig. 9, 3). Until this energization starts, the rotor 4 rotates due to inertia force during the period of no energization as described above, is accelerated by this energization, and by repeating the above-mentioned operation, the rotor 4 is further accelerated and drawn into synchronous operation. .

Next, the correction operation of the energization time T2 and detection time T3 will be explained. By applying the DC power supply 5, a constant voltage power supply ■ is generated from the constant voltage power supply circuit 9. is supplied as a control power supply, and as mentioned above, the output signal at the output terminal Q of the latch circuit LA is inverted to 'H' level by the one-shot pulse signal of the starting circuit OPC, and the delay circuit that receives this inverts to 'H' level. When the TD engineer inverts the output signal to 1H level after the standby time T0, the latch circuit LA2 becomes the pulse generator circuit M.
It is reset via B1, its output terminal Q is inverted to 'H' level, and counter circuit CU3 is reset.

This causes the comparison circuit C0M2 to switch from its output terminal A (B to '
The H' level output signal is sent to the AND circuit AND5. In response to this, the AND circuit AND5 receives at its input terminal the output signal of 1H level from the latch circuit LA, and the output signal of the delay circuit TD which is responding is 'L level' during the waiting time T. The output signal from the delay circuit TD is inverted to the H level after the standby time T, and the output signal from the delay circuit TD is inverted to the H level through the drive unit 8b. When turned on, the position detection signal is inverted to 'L level', and the edge detection section 8a
receives the pulse signal sent by T2f. This will be corrected (at the time of construction t in Figure 9). Thereafter, even if an output signal of 5H level is sent from the output terminal A (B) of the comparator circuit COM2, the AND circuit AND4.

Since the AND receives the 1H level output signal of the delay circuit TD through the NOT circuit N3 as 5L level, the output signal remains at 1L level. That is,
During the period when the stator coil 3 is energized (energization time T
2) The energization time setting circuit CU2 is not counted up or down and is not corrected.

When the output signal at the output terminal Q of the latch circuit LA2 is inverted to the 'H' level (that is, when all the transistors are turned off). Counter circuit CU3 is AND circuit AND6
Receives the same output signal as the clock signal of the oscillation circuit OSC from the output terminal of A, counts up at the rising edge of the input, and compares this with the multi-bit binary force signal.
If both Bl1 input signals are in the relationship A x B, the output terminal A (
From B, and if the relationship is A>B, from output terminal A)B.''
Sends out the H level output signal. The AND circuits AND4 and AND5 that receive this output when the output signal of the NOT circuit N3 is inverted to 'H' level (that is, the output signal of the output terminal A=B of the comparator circuit COM is inverted to 5H level, After delay time td2, the delay circuit TD2 which receives this output signal is inverted to 5H level by the edge detection section 8&o pulse signal when the 5H Lebellsch circuit LA1 is reset (at time t4 in FIG. 9). Therefore, the energization time setting circuit CU2 enters a so-called counting standby state, and counts up or down according to the pulse signal output by the edge detection section 8a at the rising edge or falling edge of the position detection signal that detects the zero point of the induced voltage. Then, the energization time T2 is corrected while maintaining the detection time T3. In other words, during the period when the energization is stopped, the next energization time T2 is corrected every 1/2 rotation period of the rotor, and the detection time T3 is thereby corrected, that is, it corresponds to the rotation speed of the rotor. By correcting the energization time T2, the energization to the stator coil is controlled to the optimum condition.

According to this embodiment, even if the standby time T is fixed in advance, the energization can be controlled by correcting the energization time T2 in accordance with the rotational speed of the rotor.

Moreover, the output terminal of the edge detection section that sends out a pulse signal based on the position detection signal is energized by the output signal of the latch circuit, which is reset with a delay time td2 from the point at which the stator coil energization is stopped. Therefore, it is possible to prevent malfunctions due to spike voltages caused by turning off the transistors of the inverter circuit, and it is also possible to simplify the configuration of the position detection circuit.

<Effects of the Invention> The rotor position is detected by stopping energization to the stator coil near the zero cross of the induced voltage, deriving only the induced voltage, and detecting its zero point. The zero point of the voltage can accurately detect the rotational position of the rotor without providing a position detection element such as a Hall element. Moreover, since a position detection element is not required, only two external lead wires are required, and the wiring can be done easily.In addition, the stator coil can be stopped from being energized and functioned as a so-called generator. Since the position detection signal level is high and the impedance is low, even if the length of the external lead wire becomes long, there will be no false detection due to noise etc., and the motor can be detected accurately and efficiently operated. Can be driven. This means that the control unit can be separated from the motor body and used as a draft animal, and there is no need to incorporate elements into the motor body, and there is no need for heat dissipation means, so it goes without saying that the motor body can be made smaller. This has great advantages, such as expanding the degree of freedom in design when installing the motor body in equipment, and making it possible to arrange the control section of the motor body in the same body as the control section of the device.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a basic configuration diagram of the motor shown in Fig. 1, Fig. 3 is a block diagram of a drive circuit showing a conventional example, and Fig. 4 is a block diagram of a conventional example. The basic configuration diagrams of the motor body shown in FIGS. 5 to 7 explain the principle of a one-phase brushless motor. FIG. 5 shows the generated magnetic flux, FIG. 6 shows the generated rotational torque, and The figure is a time chart diagram. FIG. 8 is a block diagram showing another embodiment of the present invention, and FIG. 9 is a time chart diagram explaining the wJ production of FIG. 1.10: Stator, 2.11: Stator core, 2al 2bs 11a, 111): Magnetic bottle, 3, 11
゜, 11d: Stator coil, 4.12: Rotor,
5, 14: DC power supply, 6.15: Inverter circuit, 7: Position detection circuit, 8: Energization control circuit, 8a = Workpiece detection section, 8b: Drive section, DF: @ Branch circuit, RF:
Rectifier circuit, TD, TD2: delay circuit, FF1: flip-flop circuit, AND, AND2: AND circuit, COM-C
0M2: Comparison time K,

Claims (2)

[Claims] (1) When switching the energization of a one-phase brushless motor driven by a DC power source via an inverter circuit, the energization is stopped before the induced voltage reaches zero cross and the zero point is detected, and the previous zero point of the induced voltage is detected. Measure the 1/2 rotation period of the rotor from this point to the current zero point, and use this measurement value to calculate and set the standby time from the zero point of the induced voltage to the start of energization and the energization time of the stator coil. According to the value, after a standby time is clocked from the zero point of the induced voltage, a energization command is sent to the inverter circuit to energize and drive the inverter circuit for the energization time.
How to drive a phase brushless motor. (2) An inverter circuit in which four transistors are connected to a DC power source in a bridge configuration, and freewheeling diodes are inserted in opposite directions between the collector and emitter of each transistor, and an inverter circuit is inserted between the output terminal of this inverter circuit. Between the stator coil of a one-phase brushless motor having a rotor magnetized to N and S poles and the output terminal of a constant voltage power supply circuit connected to one of the output terminals of the inverter circuit and the DC power supply, there is a collector-emitter connection. The base of the transistor inserted is connected to the position detection circuit that sends out this collector output as a position detection signal, and the rise and fall of the position detection signal of this position detection circuit are differentiated and double-wave rectified. The energization command is inputted to the drive unit via a delay circuit that outputs the output with a delay, and the energization command is sent from the drive unit to the inverter circuit, and the energization command for the drive unit is sent to the drive unit using a signal that counts the energization time from the output of the delay circuit. 1. A drive device for a one-phase brushless motor, comprising: a current supply control circuit configured to stop the stator coil, and to detect the zero point of the induced voltage by cutting off the current in the stator coil.